A pressurized-water reactor installation includes the reactor pressure vessel containing the core which heats the pressurized-water coolant circulated through the pressure vessel via a pipeline loop extending through a steam generator producing steam as useful power, and from there via a main coolant pump, back to the pressure vessel. A branch pipeline loop shunts a portion of the circulating water coolant around the main coolant pump and through a water coolant purification system, about from 10 to 20% of the circulating water coolant passing continuously through this purification system during operation of the reactor. A part of this purification system is a degassing facility wherein the water coolant is decompressed and cooled so that gases separate. These gases are mainly hydrogen, nitrogen and oxygen.
However, in addition to the above three gases the separated gases include the noble gases krypton and xenon which are present in volumes that are very small as compared to the volume of the other gases but which mandatorily prevent disposal of the separated gases by discharging them to the atmosphere.
The one prior art suggestion has been to store the separated gases under pressure in decay tanks for a time depending on the half-life of the radioactive noble gases and to thereafter discharge the gases to the atmosphere via a tall exhaust air stack through which is also discharged the exhaust air from the spherical steel containment vessel enclosing the entire reactor installation. However, this practice has been prevented by current, more stringent environmental protection regulations.
Therefore, the operation of a pressurized-water reactor installation has presented the problem of disposing of the gases separated from the water coolant during its purification, in a manner that is economically feasible and entirely safe from the environmental pollution viewpoint.